An openable wireless communication device having a movable housing and a fixed housing both of which are provided with circuit boards which are electrically coupled by a connecting part which is provided at the sides of the two circuit boards at the ends of the housings is disclosed in Japanese Laid-Open Patent Publication No. 2005-192055 (hereinafter referred to as JP-A-2005-192055). In the device disclosed in JP-A-2005-192055, due to the connecting part, the current vectors of the two circuit boards are oriented toward the power feed point of the antenna. Due to this, the ground parts formed at the two circuit boards are coupled by high frequency coupling, so the antenna characteristics are improved. This art is illustrated in JP-A-2005-192055.
In a mobile phone, to improve the antenna characteristics in the conversation state, improvement of the antenna characteristics in the conversation state where the mobile phone is in close contact with the user body, in particular, the head, is being studied. In this regard, up to now, when studying mounting of an antenna in a mobile phone, the antenna mounting has been studied while stressing the improvement of the antenna characteristics of the mobile phone when placed in free space. For this reason, the antenna characteristics sometimes deteriorated at the time of use of the mobile phone in close contact with the user body. For example, there are flip-type mobile phones and slide-type mobile phones which, in the closed state, have antennas which are carried in the housings at the user body sides at the time of conversation. In such a mobile phone, sometimes the high frequency current which flows through the housing which is positioned at the user body side at the time of conversation ends up being absorbed by the user body and therefore the antenna characteristics end up deteriorating. Even if employing the configuration described in JP-A-2005-192055 where the circuit boards of the movable housing and the fixed housing are connected by a connecting part, the electrical coupling degree was weak and control of the current vector of the high frequency current was difficult.